The use of external catheters for male urinary drainage systems is well known, as disclosed in U.S. Pat. Nos. 4,378,018, 4,187,851, 3,863,638 and 3,835,857. Essentially such a system comprises an elastic sheath adapted to fit over the user's penis, the sheath having an outlet at its distal end connected to a tube leading to a suitable collection receptacle. Since leakage resulting from fluid backflow between the penis and sheath is clearly undesirable, it has become a common practice to interpose a sealant pad between the sheath and the penile shaft as disclosed, for example, in U.S. Pat. No. 4,187,851 and in co-owned U.S. Pat. No. 4,378,018.
While a sealant pad, when properly used, performs the dual functions of preventing leakage and retaining the catheter in place, difficulties have been reported in fitting such pads and catheters upon users exactly as intended. For example, a pad of the type depicted in U.S. Pat. No. 4,187,851 takes the form of an adhesive strip intended to be wrapped about the penile shaft before the elastic catheter is unrolled into position over the penis. Performing such operations may be difficult or impossible by patients suffering from urinary incontinence since such patients often lack the motor control and/or mental acuity necessary for such manipulations. Nurses or other attendants may be unable to take the time necessary for properly wrapping and molding the sealant pads in place, and for then carefully fitting the sheaths over the pads to form leakproof seals. Should errors be made that might increase the possibilities of subsequent leakage, a nurse or attendant might nevertheless leave the improperly-applied pad and catheter in place because of time constraints or because of patient discomfort that might be associated with removing the improperly-applied pads and starting over. Moreover, problems resulting from improper application of an appliance might be more serious than occasional fluid leakage or mild patient discomfort. Thus, should an adhesive pad of the type shown in U.S. Pat. No. 4,187,851 be wrapped too tightly about the penile shaft, circulation might be impaired and tissue necrosis could result.
External catheters are currently available that are internally coated with pressure-sensitive adhesive and therefore eliminate the need for using separate adhesive-coated sealant pads. While such a construction avoids some of the more serious dangers associated with wrap-around sealant pads, the difficulties of application, and the problems of leakage resulting from improper application, persist and may even be more pronounced. Considerable care must be taken when unrolling an adhesive-coated sheath over the penis to make certain that the sheath is evenly applied without developing wrinkles and flow channels. All too frequently the adhesive-coated inner surfaces of such a sheath come into contact with each other during application of the catheter. Separation of the contacting surfaces, if possible at all, is difficult and time-consuming, with the result that corrective steps may not be taken and leakage of the catheter in later use is practically assured.
Other prior patents of general interest are Swedish Pat. No. 162,302 and U.S. Pat. Nos. 4,022,213, 4,284,079, 3,405,714, 4,239,044, 3,353,538, 3,511,241, 3,721,243, 3,631,857, 3,788,324, 3,339,551, 3,364,932, 4,296,502, and 3,742,953.